JPS62243697A - Method for washing spinner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention <Field of Industrial Application> The present invention is useful for recycling various equipment used in the manufacturing process of aromatic polyamide fibers or films, 4I&C filters, spinnerets, T-dies, etc. It concerns a cleaning method.

<Prior Art> Aromatic Polyamide Special Baller As expected from its rigid structure, oriented aromatic polyamide is a material that is expected to have high heat resistance, high strength, high modulus, etc. On the other hand, it is almost impossible to melt and mold it because it has an extremely high melting point or decomposes before melting. Therefore, when molding into fibers or films, a solution of the polymer dissolved in a solvent is usually used.
In this case, in the process of manufacturing such products, various equipment such as filters that pass through the solution, spinnerets, T-dies, etc. are used.1 These equipment are usually used to clean adhering polymers or polymer solutions. However, aromatic polyamide has extremely poor solubility in solvents, and cleaning solvents for such equipment are limited to highly corrosive concentrated sulfuric acid or fuming sulfuric acid. It is extremely difficult to efficiently recycle and clean minute parts of equipment while suppressing corrosion of the equipment.

For example, filtration filters used for forming fibers or films are replaced due to blockage due to foreign matter contained in the solution, but at that time, if the filter to be replaced is a regenerated filter that does not remove foreign matter sufficiently, During spinning or film forming, foreign matter may enter the spinning or film forming process, resulting in a decrease in the stability of the spinning or film forming, and the occurrence of fluff or scratches on the product. Alternatively, spinnerets, T-dies, and other spinnerets are washed and regenerated using corrosive solvents such as concentrated sulfuric acid, resulting in problems such as stability in yarn handling and unevenness in denier and thickness of the product. This will significantly reduce quality. Nevertheless, as mentioned above, the demand for these products has increased in recent years because useful products such as high-performance tungsten, fibers, and films can be obtained, and the equipment used to manufacture such products is Since the effects of water leakage on product quality are extremely large, there is a strong need for the development of efficient cleaning and regeneration technology.

Various methods have been tried, such as applying pressure to decompose and remove the polymer adhering to these devices using a high-temperature heating medium, or burning it off, but in all cases, residual carbide or fine parts were removed. Since the removal is incomplete, it will not be busy until it can be reused. In addition, when cleaning with concentrated sulfuric acid, a method of adding concentrated nitric acid or sulfate to suppress corrosion has been proposed (Japanese Patent Application Laid-open No. 106640/1984), but although it is effective in suppressing corrosion, ,
Fully satisfactory results cannot be obtained. J〈Problems to be solved by the invention〉 In view of the current state of the art, the present inventors have devised a method for efficiently treating equipment to which the aromatic polyamide solution has adhered, down to minute parts, without causing corrosion. As a result of careful consideration of methods for cleaning the spinning equipment, we found that the spinning equipment should be treated with dimethyl sulfoxide containing a specific alkali metal or alkaline earth metal compound, and then treated with a dimethyl sulfoxide bath containing an organic halogenated compound. The corrosion of aromatic polyamides can be significantly suppressed and aromatic polyamides can be dissolved and removed.Furthermore, compared to concentrated sulfuric acid, the viscosity of the cleaning liquid and treatment liquid is lower, so the permeability to fine parts is significantly improved, resulting in extremely high removal rate. They discovered that highly effective and efficient cleaning was possible, and after further research, they completed the present invention.

Means for Solving the Problems> The present invention provides cleaning and regeneration of spinning equipment to which aromatic polyamide or the solution has adhered, in which the spinning equipment is treated with an alkali metallized organic compound, an alkaline earth metallized organic compound, or an alkali metallized organic compound. A method for cleaning spinning equipment, which comprises treating with dimethyl sulfoxide containing at least 1 compound of metal hydrides or alkaline earth metal hydrides, followed by treatment with a dimethyl sulfoxide bath containing an organic halogenated compound.

In the present invention, the aromatic polyamide is a polymer represented by a general formula (wherein Ar1 and Ar, f1 are aromatic groups, and n is an integer), in which at least 85 moles of amide bonds are It is obtained from an aromatic cyclic diamine and an aromatic cyclic dicarboxylic acid component. Examples of its structure include polyno(linesamide, polyparaphenylene terephthalamide, poly-4,4'-diaminobenzanilide terephthalamide, polyparaphenylene-2
, 6-nutallic amide, copolyparaphenylene/
414'(L3'-dimethylbiphenylene)-terephthalamide, Kohori I (2phenylene/2eS-hy!j dylene-tele7talua ζdo, polyortho-7ethene-7thalamide, polymetaphenylene-7talamide, polypac-22-7thalamide, Polyorthophenylene isophthalamide, polymetaphenylene inophthalamide, polyparaphenylene ino-7thalamide, polyorthophenylene terephthalamide, polymetaphenylene terephthalamide, poly-1,5-su7talenephthalamide,
Poly-4,4'-diphenylene-orno-7thalamide, poly-4,4'-diphenylene inphthalamide, poly-1,4-naphthalenephthalamide, poly-1,4-
Naphthalene inphthalamide, poly-1,5-naphthaleneiso7thalamide, etc., and compounds in which a part of the benzene nucleus of these aromatic diamines is replaced with halogen, and furthermore, a part of the benzene nucleus of these aromatic diamines is Piperazine, 2,5-dimethylpiperazine, 2. Aromatic polyamides containing alicyclic amines, such as compounds substituted with s-diethylpiperazine, or aromatic diamines are
Aromatic polyamides containing two phenyl groups linked by ether groups such as 3'-oxydiphenylene diamine, 3,4'-oxydiphenylene diamine, or copolymers of the above-mentioned aromatic polyamides, such as poly-3 , 3'-oxydiphenylene terephthalamide/polyvara phenylene terephthalamide copolymer, poly-3,4'-oxydiphenylene terephthalamide/polyvara phenylene terephthalamide copolymer, and the like.

Among these aromatic polyamides, the bonding position of the aromatic group bonded through the amide bond position is the para position. Barrier-oriented aromatic polyamide is a polymer with low solubility in special solvents and is suitable for applying the method of the present invention.

In the present invention, in order to clean the spinning equipment to which the aromatic polyamide or the solution has adhered, first, one of the alkali metalated organic compounds, alkaline earth metalated organic compounds, alkali metal hydrides, or alkaline earth metal hydrides is cleaned. It is essential to treat with dimethyl sulfoxide containing at least one compound and then with a dimethyl sulfoxide bath containing an organic halogenated compound.

Simply washing with dimethyl sulfoxide cannot decompose or dissolve the polymer adhering to the spinning equipment. Treatment with dimethyl sulfoxide containing at least one compound selected from an alkali metalated organic compound, an alkaline earth metalated organic compound, an alkali metal hydride, or an alkaline earth metal hydride, and further in a dimethyl sulfoxide bath containing an organic halogenated compound. The treatment greatly promotes denaturation and dissolution, allowing efficient washing and removal.

Examples of the alkali metalated organic compound, alkaline earth metalated organic compound, alkali metal hydride, or alkaline earth metal hydride include sodium ethoxide, sodium methoxide, butyl lithium, lithium diisopropylamide, Grignard reagent, sodium hydride, and calcium. Examples include hydride.

Examples of organic halogenated compounds include methyl iodide, methyl iodide, propyl iodide, octyl iodide, stearyl iodide, ethyl bromide, propyl bromide, octyl bromide,
Examples include stearyl bromide, benzyl bromide, ethyl chloride, propyl chloride, octyl chloride, stearyl chloride, benzyl chloride, and the like.

The concentration of these alkali metalated organic compounds, alkaline earth metalated organic compounds, alkali metal hydrides, or alkaline earth metal hydrides, and organic halogenated compounds relative to dimethyl sulfoxide does not particularly limit the method of the present invention. However, if the concentration of alkali metalated organic compounds, alkaline earth metalated organic compounds, alkali metal hydrides, or alkaline earth metal hydrides, and specific halogenated compounds is low, processing and cleaning times may be increased. This may result in processing that puts pressure on the spinning equipment and an increase in the amount of cleaning solution, which is undesirable.If the concentration is high, the viscosity of the solution may increase, resulting in disadvantages in processing and cleaning operability. Alternatively, the reaction efficiency decreases and it becomes difficult to modify or dissolve the polymer attached to the spinning equipment. Therefore, in normal cases, the concentration of effective alkali metalated organic compounds, alkaline earth metalated organic compounds, alkali metal hydrides, or alkaline earth metal hydrides and organic halogenated compounds is in the range of 1 to 20 A solution prepared by is preferred.

When preparing dimethyl sulfoxide solutions of alkali metalated organic compounds, alkaline earth metalated organic compounds, alkali metal hydrides, or alkaline earth metal hydrides, and organic halogenated compounds, these compounds in dimethyl sulfoxide Simply add and dissolve.

Cleaning and treatment of spinning equipment using a dimethyl sulfoxide solution of the alkali metalated organic compound, alkaline earth metalated organic compound, alkali metal hydride or alkaline earth metal hydride, and organic halogenated compound described above This is done by immersion in a solution of

The method of dipping in this case is not particularly limited in the method of the present invention, and the dipping method of the alkali metalated organic compound, alkaline earth metalated organic compound, alkali metal hydride or alkaline earth metal hydride can be carried out as usual. This is carried out by adding a dimethyl sulfoxide solution and an organic halogenated compound to a dimethyl sulfoxide solution.

In order to carry out processing and cleaning efficiently, means such as circulating and stirring the solution are effective and have the effect of shortening the processing and cleaning time. It is also preferable to remove the polymer or polymer solution adhering to the equipment prior to cleaning by wiping or the like to an extent that does not damage the equipment, as this is effective in shortening the processing and cleaning time.

The time for treatment and cleaning varies depending on the degree of adhesion of the polymer or polymer solution to the equipment, the type and shape of the equipment, and cannot be determined unconditionally, but it is usually carried out in the range of several hours to several tens of hours. In particular, it often takes a long time for devices with dense structures such as filtration filters made of deposited and sintered metal wires. Since the corrosion resistance is low, wear and tear on equipment due to corrosion is negligible.

In the present invention, the temperature of treatment and cleaning is usually in the range from room temperature to 100°C or less. Although the effects of the method of the present invention are not particularly impaired at temperatures of 100°C or higher,
If the temperature exceeds 00°C, the evaporation of dimethyl sulfoxide and the like increases, which is not preferable.

The degree of treatment and cleaning, that is, the degree of removal and regeneration, can be determined by taking out the equipment during the cleaning process and observing it with the naked eye, under a microscope, or, depending on the case, using ventilation pressure.

During these treatments, the polymer is dissolved, removed and washed, and if necessary further treatment with dimethyl sulfoxide, dimethyl formamide, dimethyl acetamide, N-
Cleaning with a so-called amide type solvent such as methylpyrrolid 7 may also be performed.

The spinning equipment treated and cleaned in this manner is taken out of the solution, washed with water, and dried. Washing with water may be carried out by any method normally applied to such equipment, and is not limited to tR in the method of the present invention. Specifically, there are methods such as putting the equipment into clean water and washing it batchwise, immersing it in a washing tank where fresh water circulates or is being renewed, and spraying water onto the equipment. Applicable.

The equipment that has been washed with water is then dried to complete the regeneration. The drying method, conditions, etc. are not particularly limited in the present invention, and any conventionally used method may be used.

Function> This is because the aromatic polyamide polymer is N-metalized in a dimethyl sulfoxide solution containing an alkali metal compound, an alkaline earth compound, an alkali hydride, or an alkaline earth hydride compound. This causes swelling or partial dissolution, and when this N-metal salt is then treated in dimethyl sulfoxide containing an organic halogenated compound, N-substitution modification and co-occurring partial decomposition also occur, making it extremely difficult to dissolve in organic solvents. It can be inferred that it has become easier.

Dimethyl sulfoxide solutions containing alkali metalated organic compounds, alkaline earth metalated organic compounds, alkali metal hydrides or alkaline earth metal hydrides, and dimethyl sulfoxide solutions containing organic halogenated compounds have a lower concentration than concentrated sulfuric acid etc. Since it has a solution viscosity, it has excellent permeability into minute parts, and as a result, the treatment and cleaning effects are significantly improved.

As a result, when forming fibers or films using the spinning equipment that has been treated, washed and recycled using the method of the present invention, the stability during spinning or film formation is improved, and the quality of the resulting products is further improved. It will improve.

-The method of the present invention is characterized by, for example, a spinneret used for producing aromatic polyamide fibers or films;
The effect is particularly remarkable in the treatment and cleaning regeneration pressure of spinning equipment with fine structures such as filters and FiT-dies, but it is also effective in cleaning other spinning equipment, such as piping, etc. Extremely useful.

Furthermore, the method of the present invention can efficiently treat, wash and regenerate spinning equipment that is adhered to aromatic polyamides, especially barer-oriented aromatic polyamides, which have been difficult to remove by cleaning. It is possible to do so, and its effects are fully demonstrated.

<Example> Hereinafter, the present IJ1 will be further explained in detail with reference to an example, but the present invention is not limited thereto. Unless otherwise specified, the symbol "-" in the examples represents the percent i amount.

Example 1 Terephthalic acid dichloride and b-phenylene diamine were polymerized in N-methylpyrrolidone containing calcium chloride by a conventional method to obtain a hollow phenylene terephthalamide having a yinh of 8.2.

Add this polymer once to 99. One polymer was dissolved in concentrated sulfuric acid having a concentration of 19% to prepare a solution having a viscosity of 7800 mm and 775°C.

Using a spinning machine that can extrude this solution through a 70 φ sheet filter upstream of the spinneret, the solution is extruded at a rate of 10 CC/min while maintaining the solution temperature at 7.5°C.
Spinning was carried out by passing the solution through for a period of time.

The filter used at this time was 5-5 with a wire diameter of 8 to 12μ.
It is a new (unused) sintered filter made of US316 steel wire (manufactured by Nippon Seirin ■, Naslon NF-06D) (absolute diameter 10μ, thickness 0.3μ), and it is soaked with ethyl acetate and water before use. The sample was washed and dried using a water bottle, and its weight was measured in advance.

After spinning under the same conditions as described above, the filter was removed, washed and regenerated according to the method described below, and the results are shown in Table 1.

(1) Conventional method (comparative example) 500++
The filter was immersed in a beaker containing 98% Ig of concentrated sulfuric acid, kept at a temperature of 80°C, and washed for 3 days (72 hours) with sufficient stirring using a magnetic stirrer.Then, the filter was taken out and placed in running water. It was put in and washed with water for one day, then completely dried in a dryer at 130°C, and then naturally cooled in a desiccator. The weight of the obtained regenerated filter was measured.

(2) Method of the present invention (a): Add 12Of (3mo41) of 6°-purity sodium hydride washed with a small amount of n-san in a nitrogen stream to 50G-dimethyl sulfoxide,
The mixture was stirred at room temperature for 10 minutes. Then, 70'Cff1.
Ascend, stir for 30 min, and add Na Hz S (
0) tCH,/dimethyl sulfoxide solution t-adjusted. The filter was immersed in a beaker containing this liquid, heated to 80°C while thoroughly stirring with a magnetic stirrer, left for 24 hours, taken out, and then washed with octyl iodide.
gOf (2 moj) t-Dimethyl sulfoxide added 5OO- The mixture was immersed in a bath, heated to 70° C. and treated for 12 hours while sufficiently stirring with a magnetic stirrer as above. Thereafter, the filter was taken out, thoroughly washed with water, completely dried in a dryer at 110'C, cooled naturally in a desiccator, and weighed.・・・・・・・・・・・・・・・
・(W,) t(gon and (c): s o g-K in dimethyl sulfoxide (b) Potassium hydride B
6t (2moj), (c) butyllithium 19
After washing with 2f (3rmL) added,! K
(b) e (C) Both dimethyk X kphoxite 5
It was treated with a solution containing 454 t (2 moj) of 00dK benzyl chloride, washed with water, dried, and weighed.・・・・・・
...(wt)y(d) and (e) * S G O
K (d) in dimethyl sulfoxide (d) Sodium hydride 20Of (5 mot), (e) Sodium ethoxide 204 t (3 mot) was added.
The sample was treated in dimethyl sulfoxide containing 6f (2 moj) at 70°C for 20 hours. Thereafter, it was taken out, washed with water, dried, and weighed.・・・・・・・・・・・・(Wt)
(1) mentioned above? Table 1 shows the results of weighing the filters regenerated according to method (2) and calculating the weight loss rate of each from the weight. However, as shown in Table 1, the filter cleaning method according to the present invention is superior to the conventional method in terms of corrosion resistance, and
After processing the filter using the method of the present invention, we used an optical microscope to shine light on the filter surface and observe it at 100x magnification.The results showed that there was significantly less corrosion and foreign matter residue compared to regenerated filters made using the conventional method. It turned out that.

Example 2 After regenerating in Example 1, spinning was actually performed using each filter.The filter pressure loss, number of fuzz per unit length, and physical properties of fiber strength and elongation 5 hours after the start of spinning were measured. Comparative examples are shown in Table 2.

The spinning stock solution was prepared under the same conditions as in Example 1, and the specific polymer stock solution (
'M combined η1nh8.2, concentration 19% by weight, viscosity 820
0 voids/74° C.), and each filter was loaded into a nozzle pack.

The nozzle is 0.061lEIIφX100II diameter 20
Ratio using m. The spinning form is JP-A-47-3545.
According to Publication No. 8, semi-dry semi-wet spinning (distance between nozzle water surface 5
The spinning bath consists of water at a temperature of 1℃), and the discharge linear velocity is 26
．． It was wound onto a bobbin at a winding speed of 8171 m/min and a winding speed of 150 m/min, thoroughly washed with water, dried, and various measurements were performed. The bone dry denier of the yarn is I 50 d/100 f.

As shown in Table 2, the results show that the filter regenerated using the method of the present invention has a smaller pressure loss than the physical properties of fibers processed using the conventional method using an FC filter. Cleaning method (2) (a)
The processed filter was approximately twice as long as the filter processed using the conventional method (1).

Margin below Example 3 N-Methyl-2-pyrrolid 72000ad K, 20
Lithium chloride dried at 0°C 83. Pulverized particulate terephthalic acid chloride 243.69 was added to a solution in which Of and metaphenylenediamine 124.8f were dissolved, and polymerization was performed to obtain a viscous polymer solution.

The viscosity of this solution was 4,850 boids/30°C, and after adding 5.7.6 f of lithium hydroxide to this solution to neutralize the hydrochloric acid generated during polymerization, it was left to stand under vacuum for 2 hours to defoam. This was prepared for a certain period of time to obtain a stock solution for spinning. Spinning was carried out in the same manner as in Example 2, using a semi-dry and semi-humid method, the distance between the spinneret water surface was 1 O 1 Ijs, the spinning bath was a 730% aqueous solution of N-methyl-2-pyrrolid,
Using a spinning rod made of SUS a 16 with a hole diameter of 0.07 wφ x 100 holes, the yarn was drawn at a discharge line speed of 24, sm/min, and a winding speed of 1307 Fl/min.

After the spinning was completed, one of the three spinnerets used during this spinning was replaced with N containing 4.0% lithium chloride, which was used during the polymerization.
Although cleaning was performed with -methyl-2-pyrrolidone, the polymer adhering to the holes could not be dissolved and removed.

Therefore, the remaining two spinnerets were cleaned under the same conditions as in Example 1, one with concentrated sulfuric acid (method (11) of Example 1) and the other with method (2)-(a) of Example 1. Ta.

As a result of performing the same spinning experiment using a spinneret that had been regenerated using both methods, it was found that with a spinneret that had been cleaned with concentrated sulfuric acid, the raw solution could not be discharged neatly in a linear manner on the discharge surface, making it impossible to perform spinning. Ta.

On the other hand, a spinneret that has been washed with dimethyl sulfoxide containing sodium hytride and then treated with dimethyl sulfoxide to which octyl iodide has been added can be spun up without any problems, and has the same spinning stability as new yarn. No change was observed compared to when a cap was used.

<Effects of the Invention> The present invention provides spinning equipment to which an aromatic polyamide or the solution is attached, an alkali metalated organic compound, an alkaline earth metalated organic compound, an alkali metal hydride, or a dimethyl containing an alkaline earth metal hydride. By treatment with a sulfoxide solution and further treatment with a dimethyl sulfoxide solution containing an organic halogenated compound, the polymer can be denatured, dissolved, and efficiently removed. Therefore, it is possible to clean the equipment without causing wear and tear on the equipment due to corrosion, which is almost impossible to achieve with conventional cleaning methods using corrosive solvents such as concentrated sulfuric acid.

Claims (1)

[Claims] In cleaning and regenerating spinning equipment to which aromatic polyamide or the solution has adhered, the adhering equipment is treated with at least one compound selected from alkali metalated organic compounds, alkaline earth metalated organic compounds, alkali metal hydrides, and alkaline earth metal hydrides. A method for cleaning spinning equipment, which comprises treating with a dimethyl sulfoxide bath containing an organic halogenated compound, followed by treatment with a dimethyl sulfoxide bath containing an organic halogenated compound.